Variable speed drive



FIG. 1 is a front, bottom, and left side perspective view of a variable speed drive; and,

FIG. 2 is a rear, bottom, and right side perspective view thereof.

The top of the variable speed drive, to the extent it is not shown in the drawings, in hereby disclaimed as forming no part of the claimed design.

The broken lines in the drawings depict environmental subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for a variable speed drive, as shown and described. 